Mat

ABSTRACT

The present invention provides a mat ( 1, 4 ) with multiple filing chambers (10 a,  40 a ) charged gel-liked heat medium ( 12 ) and expanded by a pressure of the heat medium, wherein the filling chambers in parallel and adjacent to each other. The mat ( 1, 4 ) of the invention can keep simply and effectively a whole-body or a part of a patient warm or cool and can also prevent from bed sore.

TECHNICAL FIELD

The present invention relates to a mat which prevents bed sore and alsokeeps the body warm or cool.

BACKGROUND ART

When the body is expected to be kept in the same posture in surgicaloperation, medical care or the like, a measure for preventing bed sorecaused by interruption in blood circulation accompanied by compressionof capillaries is required.

In such a bed sore, capillaries are compressed by a patient's own weightto cause interruption in blood circulation, whereby rubefaction of theskin starts, and the condition gradually becomes serious.

In order to prevent the interruption in blood circulation by thiscompression, for example, a decompression tool such as an air mat, aresinous mat or a beads-filled pad has been hitherto used so as not toconcentrate a pressure on a contact site between the human body and amat or the like.

However, for example, since an air mat is quite resilient, it has beenproblematic in stability of an operation site during surgical operation.Further, it has been excessively collapsed to give no satisfactoryeffect of preventing bed sore, and have involved problems in size,maintenance, noise of an air pump and the like.

The resinous mat includes those using a urethane foam and a dry polymer(trade name: ACTON DRY POLYMER).

Of these resinous mats, a certain effect of dispersing a contactpressure might be expected, but prevention of bed sore is notsatisfactory.

In addition, there is, for example, a beads-filled pad in which expandedresin beads are accommodated in a woven fabric enriched instretchability or the like. However, this has been, like the resinousmats, also unsatisfactory in preventing bed sore.

Further, mere rubefaction accompanied by interruption in bloodcirculation is, in some conditions such as a patient's state and anoperation time, developed into more serious bed sore during surgicaloperation or in perioperative absolute rest which has quite an adverseeffect on recovery of a patient.

In order to avoid this situation, observation of a site in whichoccurrence of bed sore is expected and a change of a posture are quiteimportant.

However, even during surgical operation or before or after surgicaloperation, the observation of the site or the change of the posture issometimes impossible in some state of a patient. In this case, it hasbeen impossible to prevent bed sore.

Even though the observation of the site or the change of the posture hasbeen possible, it has been required to conduct the same by doctors, malenurses or nursing-care persons. Thus, there has been a problem that aload of nurses and the like is great.

In case of a patient suffering from disturbance of consciousness ordisorder of moving function, bed sore could not have been preventedsufficiently even with an ordinary decompression tool. Accordingly,there has been a problem that nursing-care persons and the like have tooften change the posture which invites a great load.

As a mat from which the effect of preventing bed sore is expected, thereis a waterbed.

However, since a patient's body is sunk too much in the waterbed,occurrence of bed sore cannot be prevented satisfactorily.

The waterbed has been problematic in that it is itself large-scaled,quite heavy, hard to perform installation, movement or the like, costly,and unrealistic when used in hospitals, in nursing-care institution orat home.

A problem to which attention has to be paid during surgical operation isto prevent shivering accompanied by abrupt decrease in body temperature.

The temperature inside the human body is from approximately 38 to 40°C., though it varies with the age, the sex, the condition of diseasesand the like. For example, when surgical operation of abdominal sectionis performed in an operating room at room temperature of approximately25° C., a body temperature of a patient is decreased at once to causeshivering.

In surgical operation, it is therefore necessary to control the bodytemperature. Warming has been hitherto conducted using a warming toolsuch as a warm air heater, a warm air mat or a warm watercirculation-type blanket lest the patient's body temperature should bedecreased.

Nevertheless, such an ordinary method has involved problems that adevice such as a heater has to be put near an operating table, it isobstructive and noisy, and the device itself is liable to get out oforder.

When these warming tools are, like a warm water circulation blanket,laid under a patient, they have to be inserted between a decompressiontool and a patient upon taking preference for keeping warm. In thiscase, the decompression effect is notably decreased.

On the contrary, upon taking preference for decompression, thedecompression tool has to be put between the warming tool and thepatient, and the effect of keeping the body temperature is decreased.

Thus, keeping the body temperature in surgical operation iscontradictory to prevention of bed sore.

As a device having both the function of keeping the body temperature andthe function of preventing bed sore, there is a resinous mat having acord heater embedded therein.

However, there have been problems that the resinous mat itself does nothave a satisfactory function of preventing bed sore and the cord heatertends to get out of order owing to disconnection or the like.

With the advancement of the aging society, the number of bedriddenpersons is increased, and prevention of bed sore is a serious problem innursing care in institution or at home. However, there is no simple andeffective mat that can solve this problem. At present, there has been nochoice but to rely on manual labor of nursing-care persons and the like,inviting a problem of a great burden.

When a whole body or a predetermined site of a lying patient has to becooled, a cooling tool such as an ice pack is sometimes inserted betweenthe patient and a bed or the like.

In this case, the cooling tool is closely adhered to a region in whichcapillaries are compressed by the weight of the patient to interruptblood circulation. Thus, it has involved problems that frostbite mightoccur and interruption of blood circulation is accelerated to prompt bedsore.

For this reason, when cooling is conducted using an ordinary coolingtool such as an ice pack, a contact portion of the cooling tool and acondition of blood circulation and a cooling state in the contact regionhave to be confirmed at any time. Thus, there has been a problem that ittakes much labor to control the conditions.

Accordingly, the invention aims to provide a mat which can prevent bedsore and keep a whole body or a part of a patient warm or cool simplyand effectively.

DISCLOSURE OF THE INVENTION

The present inventors have assiduously conducted investigations to solvethe foregoing problems, and have consequently found that it is possibleto prevent bed sore and keep a whole body or a part of a patient warm orcool simply and efficiently using a mat in which multiple fillingchambers formed of flexible sheets and arranged such that they are inparallel and adjacent to each other are provided, a gel-like heat mediumis charged into the filling chambers, and the filling chambers areexpanded by a pressure of the heat medium. This finding has led to thecompletion of the invention.

That is, the invention is specified by the following (1) to (8).

(1) A mat comprising multiple filling chambers which are in parallel andadjacent to each other, wherein the filling chambers are formed offlexible sheets, a gel-like heat medium is charged into the fillingchambers, and the filling chambers are expanded by a pressure of theheat medium.

(2) The mat recited in (1), wherein the heat medium is charged into thefilling chamber by charging the heat medium into a bag capable of beinginserted closely into the filling chamber, inserting the bag having theheat medium charged therein into the filling chamber and sealing thefilling chamber.

(3) The mat recited in (1) or (2), wherein an emboss formed by bondingpredetermined regions of wall surfaces forming the filling chamber andopposite to each other is provided in the vicinity of at least one endof the filling chamber.

(4) The mat recited in (1) or (2), wherein the sheets forming thefilling chamber are a pair of opposite thermoplastic resin sheets whichare heat-bonded along the contours of the filling chamber to define thefilling chamber.

(5) The mat recited in (1) or (2), wherein flexible fins are providedwhich are extended outwardly from at least a part of margins.

(6) The mat recited in (1) or (2), wherein the heat medium is a warmingmaterial.

(7) The mat recited in (1) or (2), wherein the heat medium is a coolingmaterial.

(8) The mat recited in (1) or (2), wherein the heat medium is ahydrogel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view showing a first working example of a mat accordingto the invention.

FIG. 2 is a sectional end view taken on line A-A shown in FIG. 1.

FIG. 3 is a partial explanatory view showing an example of a use stateof the mat shown in FIG. 1.

FIG. 4 is a top view showing a second working example of the mataccording to the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The invention is described in detail below by referring to drawings.

To begin with, the first working example of the mat according to theinvention is described on the basis of FIG. 1 and FIG. 2.

A mat 1 comprises a mat portion 10, fins 11 and a heat medium 12.

The mat portion 10 is formed by overlaying a pair of rectangular sheetsmade of a thermoplastic resin and bonding both of the sheets along thecontours of a filling chamber 10 a through melt-bonding with ahigh-frequency welder or the like.

Five such filling chambers 10 a are defined in a long rectangular shapealong a longitudinal direction of the sheets such that they are inparallel and adjacent to each other.

In the filling chambers 10 a, the heat medium 12 is filled the processof the definement of the filling chambers 10 a, and sealed within thefilling chambers 10 a.

As a filler 12, a hydrophilic polymer containing a large amount ofwater, namely a hydrogel, is used.

In order to increase a pressure of the heat medium 12 within the fillingchambers 10 a, regions opposite to each other in the sheets of wallsurfaces forming the filling chambers 10 a are heat-bonded circularly toform embosses 10 b in the vicinity of both ends of the respectivefilling chambers 10 a. Consequently, the filling chambers 10 a arestrongly expanded by the pressure thereof as shown in FIG. 2.

The fins 11 are rectangular thermoplastic resin sheets which have thesame width as opposite edges on end sides of the filling chambers 10 ain the mat portion 10 and which are heat-bonded to the mat portion 10 soas to be extended outwardly from the opposite ends.

When the mat 1 is used, the mat 1 is first stored in a warming box notshown, and warmed satisfactorily until the heat medium 12 reaches apredetermined temperature.

This warming box is adapted to be warmed at an appropriate temperatureof less than 50° C., and the mat 1 stored therein is warmed by radiationheat or conduction heat.

Since the temperature of the surface of human body is generally from 32to 33° C., it is advisable that the warming box can warm the surface ofthe mat 1 at from approximately 34 to 36° C.

Next, the mat 1 warmed satisfactorily is withdrawn, and installed in adesired position on a mattress 21 of an operating table 2 such that thefins 11 are hanged from both sides of the operating table 2.

The fins 11 hanged on both sides of the operating table 2 are thenrolled, as shown in FIG. 3, under the mattress 21, and inserted intogaps between a base 20 and the mattress 21. Further, it is covered witha sheet 3, and the margins of the sheet are also rolled under themattress 21, and inserted similarly.

When a patient lies on the operating table 2 with the mat 1 installed inthis manner, the body of the patient is held by the multiple fillingchambers 10 a expanded in the shape of a nearly round rod.

At this time, the filling chambers 10 a support the body of the patientwith an appropriate hardness without concentrating a load on the contactsurface with the mat 1. Thus, compression of capillaries does not occur.

Since the patient is kept warm with the warmed mat 1 to stimulate bloodcirculation, the bed sore does not occur.

When the abdominal operation is performed, the body temperature is notrapidly decreased owing to the warming effect of the mat 1, so thatshivering can be prevented.

At the time of using the mat 1, the mat 1 allows insulation with thebody of the patient or the cover put on the patient, so that the warmingeffect is maintained for a long period of time.

Accordingly, in surgical operation over a long period of time,occurrence of bed sore or shivering can be prevented.

Next, a second working example of the mat according to the invention isdescribed on the basis of FIG. 4.

By the way, since the main construction of this working example is thesame as that of the first working example, different points thereof aremainly described.

A mat 4 has seven filling chambers 40 a in which a heat medium has beencharged.

These filling chambers 40 a are strongly expanded by a pressure thereofwhich is increased with embosses 40 b.

This mat 4 is appropriate as a pad of a cushion for a wheelchair.

In a wheelchair on which the cushion for a wheelchair having this mat 4accommodated therein has been installed, rubefaction or bed sore doesnot occur on the skin of a wheelchair user in contact with the cushioneven though the user sits thereon over a long period of time.

In this case, the cushion may be used while being warmed at anappropriate temperature by warming the mat 4 before use or mounting aheater in the cushion itself.

It is recommendable that an insulation layer such as an urethane mat isdisposed between the mat 4 and the sitting surface of the wheelchair soas to accumulate the body temperature of the user in the mat 4efficiently.

This working example is constructed as mentioned above. An appropriatematerial of the sheets and the fins constituting the mat is an ethylenefilm in view of a processability, a strength and the like. However, thisis not critical.

Different materials may be used in the sheets constituting the matportion and the fins, and different materials may also be used in thepair of sheets constituting the mat portion.

Specific examples of the heat medium include poly(N-vinylacetamide),polyvinyl alcohol, polyethylene oxide, polyvinyl pyrrolidone,carrageenan, alginic acid, sodium carboxymethylcellulose, carboxymethylstarch sodium salt, polyacrylic acid, sodium polyacrylate,polyacrylamide, agar, polyaspartic acid, sodium polyglutamate,poly(ε-lysine) and the like. However, these are not critical, and pluralhydrogels may be incorporated.

As the hydrogel, a hydrogel obtained by mixing a hydrophilic polymersuch as polyvinyl alcohol, polyethylene oxide or polyvinyl pyrrolidonewith water and applying radioactive rays to the mixture to cause acrosslinking reaction may be used.

With respect to the size of the mat according to the invention, in caseof, for example, a mat having five filling chambers as shown in FIG. 1,the length of the filling chamber is 500 mm, the width over all of thefilling chambers is 300 mm, the diameter of the emboss is 20 mm, and theheight near the center of the filling chamber expanded when put on aflat surface is 30 mm, so that the weight is approximately 3 kg. Thismat is then easy to use.

The number of the filling chambers is not limited to five, and it may befour or less, or six or more according to the use purpose.

For example, in case of a mat having four filling chambers, the lengthof the filling chamber is 500 mm, the width over all of the fillingchambers is 238 mm, the diameter of the emboss is 20 mm, and the heightnear the center of the filling chamber expanded when put on a flatsurface is 25 mm, so that the weight is approximately 2 kg. This mat isthen easy to use.

The size of each portion constituting the mat and the number of thefilling chambers vary with the use purpose and the use conditions, andthe foregoing sizes are naturally not critical. They can properly bechanged within the range of the invention. However, when the mat islarge-sized or the number of the filling chambers is increased, theweight and the bulk are increased, and the mat is hard to handle.

Accordingly, when the mat is put over a wide area, it is recommendablethat a combination of plural mats having the foregoing sizes is used bybeing set on positions on which the head, shoulders, arms, buttocks,legs, heels and the like are placed.

The mat according to the invention has the greatest characteristicfeature that the body can be held by using, as a cushion, the fillingchambers expanded by the pressure of the gel-like heat medium, and theconstruction of the details is not limited to the forgoing workingexamples. For example, with respect to the sheet constituting the matportion and the fins, any sheet will do so long as it has a flexibility,a water resistance and a strength that withstands the use and can beprocessed into a desired shape. For example, it may be afiber-reinforced sheet which is reinforced with a nonwoven fabric or awoven fabric or a composite material obtained by laminating pluralmaterials.

A method for defining the filling chambers is not limited to theforegoing working examples. For example, the filling chambers maybeformed by connecting the filling chamber portions formed in the shape ofa round rod in parallel or by bonding the surface sheet in a wavy stateto the flat reverse sheet.

The embosses provided to increase the pressure of the heat medium filledin the filling chambers are not necessarily provided so long as thepressure of the heat medium can fully be secured by filling the heatmedium. The number, the shape and the area of the embosses can freely bechanged so long as the embosses can expand the filling chamberssatisfactorily.

The heat medium is not directly charged into the filling chamber but maybe charged into the filling chamber by, for example, previously chargingthe heat medium into a long bag having approximately the same shape asthat of the filling chamber, inserting the bag into the filling chamberand sealing the filling chamber. In this case, the work of charging theheat medium becomes easy, and leak of the heat medium due to breakage ofthe filling chamber can be prevented.

This bag may have any shape so long as it can closely be inserted intothe filling chamber, and plural bags may be inserted into one fillingchamber.

A method for fixing the mat on an operating table, a bed or the like isnot limited to using the fins. For example, a surface fastener which canfreely be attached to or detached from the sheet or the mattress may beput on the reverse surface of the mat, or plural fixing methods may becombined.

A fin-free mat may be put into a bag, a cover or the like, and fastenedon the operating table. A desired stopper may be provided on the mat forfixing.

Plural mats may be installed on a mat holder capable of installingplural mats, and placed on a bed, so that the mats are not slid by theweight of the mats during use.

Any method for installing the mat on a bed or the like is available solong as the mat is not slid during use.

For some use purpose, an installation unit such as fins is notnecessarily provided.

In the foregoing working examples, the hydrogel is used as the heatmedium. Accordingly, this mat can be cooled in a cooling chamber or thelike and used as a cooling mat.

As the heat medium, any gel-like heat medium may be used.

As this heat medium, a heat medium for keeping warm and cool isgenerally used. A heat medium for keeping warm only or for keeping coolonly is also available.

When the mat according to the invention is used for cooling,interruption in blood circulation due to compression does not occur incapillaries around an affected part, with the result that the affectedpart can be cooled properly.

In the working examples, the mat is used by being fixed on the operatingtable. The mat is used not only during surgical operation, but also in ausual bed or mattress. Further, the mat can be used in any environmentsuch as an institution of medical care, an institution of nursing careand home. The posture of a user includes lying with his face upward,lying with his side, lying with his face downward and the like. Aspecial posture according to the necessity of medical treatment ormedical care is also available.

The field of using the mat according to the invention is not limited tomedical treatment, welfare and nursing care. For example, the mat may beutilized in a kneeling cushion, a cushion, a pillow and various pads bychanging the length and the width of the mat and the number of thefilling chambers.

When the mat according to the invention is used as a cushion of a chairfor office work, a person can continue work efficiently without feelingpain in the buttocks even though sitting for a long period of time.

The mat according to the invention may be used without being warmed. Atthis time, the body temperature of a user is accumulated in the heatmedium charged in the filling chambers, and the mat exhibits the sameeffect of keeping warm as the mat previously warmed during use.

EXAMPLES

The invention is illustrated more specifically by referring to Examples.However, these Examples are mere working examples, and do not limit theinvention. They may be changed without departing from the scope of theinvention.

The test was conducted using the same mat as shown in FIG. 1.

With respect to the size of the mat used, the length of the fillingchamber was 500 mm, the width over all of the filling chambers was 300mm, the diameter of the emboss was 20 mm, and the height near the centerof the filling chamber expanded when put on a flat surface was 30 mm.

The mats were warmed in a warming box for a predetermined period oftime. The warmed mats were fastened in parallel on a hard top plate, anda sheet was put thereon.

At this time, the surface temperature of the mats was 34° C.

The inventor lay on the mats through the sheet with his face upward, andwas covered with a blanket from feet to shoulders.

He kept a rest with this posture. After the lapse of 10 hours, thecondition of the skin around the blade bone, the sacred bone and theheels was observed. Consequently, rubefaction did not occur in any ofthese positions.

The surface temperature of the mats was 33° C., and this temperature wasalmost unchanged.

The results revealed that the use of the mats could prevent bed sore andmaintain the effect of keeping warm for a long period of time.

INDUSTRIAL APPLICABILITY

The mat can prevent bed sore and keep a whole body or a part of apatient warm or cool simply and effectively.

When the mat is used as a measure for preventing the decrease in bodytemperature of a patient in surgical operation, there is no need tobring extra devices or the like into an operating room, so that surgicaloperation can proceed smoothly.

When there is a warming box or a refrigerator, the mat can easily beused not only in an institution of medical treatment and an institutionof nursing care, but also at home to decrease a load of nursing-carepersons and the like.

1. A mat comprising multiple filling chambers which are in parallel andadjacent to each other, wherein the filling chambers are formed offlexible sheets, a gel-like heat medium is charged into the fillingchambers, and the filling chambers are expanded by a pressure of theheat medium.
 2. The mat as claimed in claim 1, wherein the heat mediumis charged into the filling chamber by charging the heat medium into abag capable of being inserted closely into the filling chamber,inserting the bag having the heat medium charged therein into thefilling chamber and sealing the filling chamber.
 3. The mat as claimedin claim 2, wherein an emboss formed by bonding predetermined regions ofwall surfaces forming the filling chamber and opposite to each other isprovided in the vicinity of at least one end of the filling chamber. 4.The mat as claimed in claim 2, wherein the sheets forming the fillingchamber are a pair of opposite thermoplastic resin sheets which areheat-bonded along the contours of the filling chamber to define thefilling chamber.
 5. The mat as claimed in claim 2, wherein flexible finsare provided which are extended outwardly from at least a part ofmargins.
 6. The mat as claimed in claim 2, wherein the heat medium is awarming material.
 7. The mat as claimed in claim 2, wherein the heatmedium is a cooling material.
 8. The mat as claimed in claim 2, whereinthe heat medium is a hydrogel.
 9. The mat as claimed in claim 1, whereinan emboss formed by bonding predetermined regions of wall surfacesforming the filling chamber and opposite to each other is provided inthe vicinity of at least one end of the filling chamber.
 10. The mat asclaimed in claim 1, wherein the sheets forming the filling chamber are apair of opposite thermoplastic resin sheets which are heat-bonded alongthe contours of the filling chamber to define the filling chamber. 11.The mat as claimed in claim 1, wherein flexible fins are provided whichare extended outwardly from at least a part of margins.
 12. The mat asclaimed in claim 1, wherein the heat medium is a warming material. 13.The mat as claimed in claim 1, wherein the heat medium is a coolingmaterial.
 14. The mat as claimed in claim 1, wherein the heat medium isa hydrogel.